Off center vinyl pressing

I mean that with most off-center records, one side is "more" off-center than the other. That is, the two sides are not centered even relative to each other. Because the two negative stamps against which the vinyl is pressed do not properly align, due to some mechanical play in the press or simply because they are not well centered to begin with. So Side A will have a different absolute center than Side B, geometrically speaking. Therefore, two overlapping holes would be needed to account for each side.

 

Usually there are not many off-center records in ones collection, so manual centering is not a biggie and you can do it only once and mark the position, not every time you play the record.

This spindle is pricey but worth it if one goes the Technics mod path. If made as a standard at the factory it will cost nothing.

What I dislike about your system is that it heavily messes with the original tt electronics. I don't see that's worth it for few off-center records.

 

I'm a computer engineer in the 21st century. Therefore I'm feeling very confident about heavily messing with original tt electronics of the 70s.

 

VERY good job! my compliments

 

This statement doesn't offer any counter argumentation on why it is better to mess with the tt motor's rotational stability (an essential tt characteristic that even renowned manufacturers have problem achieving in the 21 century, as we can see) instead of changing the spindle or make it removable - a simple physical solution that targets the problem with precision and no side effects.
Doing it for fun is cool, but seems pretty complicated in comparison to the mentioned existing solution.

 

We've managed to land a spacecraft on a comet recently, yet somehow you believe that humanity still haven't grasped the science of achieving rotational stability in turntables?! Many "renowned" manufacturers are using early 1960s technology in their "21st century" turntables, so they feel justified to ask multi-thousand (or tens of thousands) price figures for their "better" ones. Rotational stability is something achieved using constant-torque motors and clever servos, which were already available in the early 80s, not pursued with "exotic" materials, enormous rotating mass and judged in "listening sessions". As for off-center records, a basic computation will show you that having as little as +/-0.5mm offset of the absolute center will yield +/-0.714% of "wow" towards the end of the record, where the groove radius is 7cm. Show me any decent DD turntable that has worse rotational stability than this! But indeed, if you're considering a "turntable" like this one , I totally agree that my work is utter nonsense.

Soon after shooting my video, I wrote to Thorens about it. Their CEO called me on the phone on the same day to express his enthusiasm and firm desire to "use my work" in at least some of their upcoming products. He even mentioned their (back then) planned new DD turntable which would be suitable to support it. Only to never contact me again, or reply to my email. This can give you an idea about how "serious" renowned manufacturers are today. And Thorens really is one of the more "sensible" ones, in my opinion.

 

No doubt the rotational stability is not a rocket science in this day and age and the manufacturers are profit driven and manipulative. Thing is why complicate when there is a simple solution? You are shooting a mosquito with bazooka. Thorens or any other manufacturer needs to just include an interchangeable spindle and that's all, which is a minimal investment for them, unlike the system you created.

 

For me it would be solving a problem I don´t have, like using a device to put on my cap.

 

People do it all the time in this day of age, whether it's dimming their lights from their smartphone or having keyless entry on their car. It's called convenience, and I am against it myself in many instances. Just as others choose to trade convenience for the satisfaction of doing something themselves, instead of using something that's readily available. And I lean towards valuing the latter. Whether it's manually centering a record on your turntable (which I also used to do), or implementing a more complex solution like mine. In the end it's about what gives you the most satisfaction. Nakamichi have gone to a great distance to address the problem with their TX-1000 and later Dragon CT, and they have all my praise for doing so. And Nakamichi isn't exactly known for adding useless gimmicks and bells and whistles to their products. Quite the opposite, in fact.

 

Why wear a cap in the first place?

 

Because I don´t feel well dressed without one. But You get my picture on the topic of non centered holes. I don´t have any problem with non centered holes.

 

How????????

 

Oh I get it. As long as there's a hole... and you're wearing a cap.

 

Ok, so what is your intention with this system? Made it just for fun, sell it to a tt company for serial production, offer it to individual vinyl enthusiasts...?

 

I already told you how my acquaintance with Thorens went; I tried to contact a couple of other manuf's recently, but got no reply. Thorens seemed by far the most serious and "down-to-earth". I posted here to reach out anybody who might be interested, maybe they can help in that direction. The most I could achieve on my own would be an "upgrade kit" for the SL-1200MK2 and others from the lineup which use the same motor / tonearm arrangement.

 

Well, watch the patent applications online to see when they start filing, so you can dispute it. Lawyers probably told him "screw some guy in Romainia, we get it".

Thought I'd do a quick patent search, didn't find anything novel except Hanpin patented a system to lift the tonearm at the end of the record. Thought you guys might enjoy this complete idiot's 2018 patent application though, a pivoting headshell "to allow the cartridge to track along the direction of the tangent..." obviously someone who has no clue about the basics of turntable dynamics:
HEADSHELL AND TONEARM FOR MOUNTING CARTRIDGE OF AUDIO TURNTABLE AND AUDIO TURNTABLE COMPRISING SAME - SON Dong-Chan

....Pivoting headshells have been around forever, to dramatically demonstrate out-of-whack antiskate and to refine antiskating designs, and this patent can never work to play a record properly.

..

Anyway, to improve the correction, an idea and invention released free worldwide to the public domain in perpetuity, also obvious to someone skilled in the art: using one of easily available timecode vinyl (for DJing) and its encoded stereo phase information to learn the hysteresis loop and response delay of the turntable motor. By subjecting the turntable to increasing speed anomalies via its motor control, simulating the corrections needed for out of center records, a one-time calibration can be performed by monitoring the audio response. Free and open source timecode tracking software, such as that in Mixxx, can be adapted as a code base. The cartridge output can temporarily be switched over to an ADC with little gain or EQ needed to understand the audio, if a user-recalibratable system is desired.

 

My green vinyl copy of Real Estate’s ‘Atlas’ is noticeably - and very audibly - pressed off-centre. Went to return it, but no copies left, so kept it. Very frustrating.

 

You enlarge the hole slightly in the right direction. It actually works well for medium-light off center records. The technique is described on here somewhere in detail.

 

Of the talks using an interchangeable spindle, how would that help to make an accuracy 0f 0.1 mm or better?

 

Thank you, Harby. I remember seeing the patent application you've posted. As you can imagine, I've been looking too to see if anyone else had done something similar, but couldn't find anything. As for Thorens trying to rip me off, I can't imagine why, because I offered them my support as an external consultant and I didn't ask for anything (although the CEO even went ahead and asked me this when I spoke to him). I think it would have been beneficial to them, both in development cost and certainly in speed. And I certainly wouldn't have asked for much in return, seeing my "baby adopted" would have been a great achievement on its own. Most probably they decided that their usual customers would not be interested in such a feature, some maybe even criticize them for going for something so "modern" and unproven. Still, never contacting me again was... unexpected from someone on this level.

 

You already suggested this to me yesterday, only not in such detail Off center vinyl pressing
When the day comes that manufacturers come begging to license my invention (as they undoubtedly will), I'll make sure you get your fair share of the loot.
Again, this is a neat idea, but my silly 8-bit 8KB flash uC which I'm currently using needs to be upgraded in order to add this feature.

 

Damaging the record aesthetically?

 

If you can't hear any wow or warble, it isn't a problem.

 

Yes, 0,55Hz is such a low frequency that it's very unlikely we hear normal variations in off center. If we could not many would play records.

 

You could take that view, of course. But what use is a record that weaves in an out on your turntable causing stress to your cartridge/stylus/cantilever? For me the real aesthetic is the sheer beauty of a correctly centred disc being tracked by a diamond attached to a cartridge in a tonearm! Some will say, 'bah, old technology' but it is a very beautiful thing, pretty amazing and is a technological wonder. I get your point, of course, and it is well made.

You would however be startled at how good you become at 'adjusting' spindle holes that are off centre. The 'adjustment' to the spindle hole is usually invisible, pretty much'. I have fixed many hundreds of spindle holes, some only very mildly off centre, I admit. However, now and then I go back to a disc that I have fixed many years ago and am amazed at how good it looks. Nobody, and I mean nobody, would ever know that the spindle hole had to be altered. My copy of X 'Wild Gift' (Porterhouse Reissue 2007 or so) was badly off centre on one side. I fixed it and it now revolves concentrically. If you looked at the spindle hole, you would think that this is how it came out of the pressing plant. Sometimes also, paper from the centre label can extend over the spindle hole and this can cause eccentricity. You just need to shave the excess paper, carefully, and you're all set! Of course, when you start this practice initially, you can be a little bit enthusiastic and you can enlarge the hole too much. With practice you can become very good at doing it very well and without ruining the aesthetics. Very few pressing plants, punch super clean centre holes in my experience, anyway? Optimal is one plant which does produce very neat and precise spindle holes (they aren't always centred either!) and Pallas used to, at one time, but most plants do not.

I do not think you can do anything with a disc that was pressed on a badly set up press where the stampers were incorrectly aligned? It is not the spindle hole that is wrong in this case.